PROTECTION STATUS: Not listed
PETITIONED: 2003
RANGE: Around the Pacific Rim from Japan through Alaska, British Columbia, Washington, Oregon, and California, down to Baja California, Mexico
THREATS: Habitat losses due to reduced river flows, water diversions, dredging, streambed scouring, channelization, inadequate protection of streamside vegetation, chemical pollution and spills, and impeded upstream passage due to dams and poorly designed road culverts
POPULATION TREND: The species has declined throughout its range in California, Oregon, Washington, and Idaho, with the most precipitous documented declines in the upper Columbia, Snake, and North Umpqua river basins.